In a typical automotive air conditioning system, refrigerant is compressed by a compressor unit driven by the automotive engine. The compressed refrigerant, at high temperature and pressure, enters a condenser where heat is removed from the compressed refrigerant. The refrigerant then travels through a receiver/drier to a thermal expansion valve. The thermal expansion valve throttles the refrigerant as it flows through a valve orifice, which causes the refrigerant to change phase from liquid to a saturated liquid/vapor mixture as it enters the evaporator. In the evaporator, heat is drawn from the environment to replace the latent heat of vaporization of the refrigerant, thus cooling the environmental air. The low-pressure refrigerant flow from the evaporator returns to the suction side of the compressor to begin a new cycle.
The condenser is a device used to change the high-pressure refrigerant vapor to a liquid. The condenser is always mounted directly in front of the vehicle radiator. The vapor is condensed to a liquid because of the high pressure driving it in, which generates a great deal of heat. The heat is then removed from the condenser by air flowing through the condenser on the outside. The condenser contains a drier bottle located on the high-pressure section of the condenser that acts as the temporary storage container for the oil and refrigerant when neither is needed for system operation. The drier bottle typically contains a plug on the bottom seal of the drier bottle. Typical condensers also include pressure sensors contained on the condenser on the opposite side of the drier bottle.
Typically, the drier bottle plugs are made of plastic or aluminum and inserted into the bottom of the drier bottle. The plug seal is completed with the assistance of O-rings. The plastic thread-in plugs thread into the aluminum threads contained on the drier bottle. The threading of the plastic threads from the plugs, into the aluminum threads on the drier bottle, results in problems associated with cross threading. Further, debris caused by the plastic threads within the tight aluminum threads due to over torqueing or under torqueing on the assembly line results in debris being trapped inside the condenser and ultimately inside the entire air conditioning system, as they are closed loop systems. The condenser sensor is a separate additional part contained on the opposite side of the condenser as the drier bottle. Integration of the sensor into the condenser's drier bottle plug reduces the overall weight of the condenser, reduces the amount of components required for use with the condenser and reduces the costs associated with the machining of block fittings and the required port fitting with Schrader valve needed to secure the sensor to the condenser or elsewhere in the system such as the directly on an AC line or on a non-condenser mounted receiver drier.